Phthalocyanines And Their Use In Ink-Jet Printers

ABSTRACT

A mixture of dyes of Formula (1) and salts thereof:  
                 
wherein: M is 2H, Si, a metal, an oxymetal group, a hydroxymetal group or a halometal group; 
 
Pc represents a phthalocyanine nucleus of formula  
                 
         R 1  and R 2  independently are H or optionally substituted C 1-4 alkyl; L is a divalent linking group; B is a substituent. x is 0.1 to 3.8; y is 0.1 to 3.8; z is 0.1 to 3.8; the sum of (x+y+z) is 2 to 4; and the substituents, represented by x, y and z, are only attached to a β position on the phthalocyanine ring and the dyes are free from fibre reactive groups. Also novel compositions and ink-jet printer inks, processes and cartridges.

This invention relates to dyes, compositions and inks, to printing processes, to printed substrates and to ink-jet printer cartridges.

Ink-jet printing is a non-impact printing technique in which droplets of ink are ejected through a fine nozzle onto a substrate without bringing the nozzle into contact with the substrate.

Colour ink-jet printers typically use four different coloured inks; magenta, yellow, cyan, and black. Colours other than these may be obtained using differing combinations of these inks. Thus, for optimum print quality, the colourants used must be able to form an ink with a specific precise hue. This can be achieved by mixing colourants but is advantageously achieved by used a single colourant with the exact hue required.

While ink-jet printers have many advantages over other forms of printing and image development there are still technical challenges to be addressed. For example, there are the contradictory requirements of providing ink colorants that are soluble in the ink medium and yet do not run or smudge excessively when printed on paper. The inks need to dry quickly to avoid sheets sticking together after they have been printed, but they should not form a crust over the tiny nozzle used in the printer. Storage stability is also important to avoid particle formation that could block the tiny nozzles used in the printer especially since consumers can keep an ink-jet ink cartridge for several months.

With the advent of high-resolution digital cameras and ink-jet printers it is becoming increasingly common for consumers to print off photographs using an ink-jet printer. This avoids the expense and inconvenience of conventional silver halide photography and provides a print quickly and conveniently. However this use of ink-jet printers requires that the prints should display an outstanding fastness to light and common oxidising gases such as ozone. Photographs, once printed, are often kept on display for years and it has been found that even apparently small changes in the light and ozone fastness of a print in a test systems can correlate to a significant improvement in the fastness of the image in real life.

Most cyan colorants used in ink-jet printing are based on phthalocyanines and problems of fading and shade change on exposure to light and contact with ozone are particularly acute with dyes of this class.

Phthalocyanines bearing sulfonate and sulfonamide substituents have found particular utility in ink-jet printing. These dyes are usually made by sulfonating a phthalocyanine pigment followed by chlorination and then amination/amidation, the resultant product carries sulfo and sulfonamide/substituted sulfonamide substituents in any susceptible position (for example see Schofield, J and Asaf, M in Journal of Chromatography, 1997, 770, pp 345-348).

However we have found that certain phthalocyanines substituted only in the β-position display advantageous properties when used in ink-jet printing.

The present invention provides a mixture of dyes of Formula (1) and salts thereof:

wherein:

M is 2H, Si, a metal, an oxymetal group, a hydroxymetal group or a halometal group;

Pc represents a phthalocyanine nucleus of formula

R¹ and R² independently are H or optionally substituted C₁₋₄alkyl;

L is a divalent linking group;

B is a substituent.

x is 0.1 to 3.8;

y is 0.1 to 3.8;

z is 0.1 to 3.8;

the sum of (x+y+z) is 2 to 4;and

the substituents, represented by x, y and z, are only attached to a β position on the phthalocyanine ring and the dyes are free from fibre reactive groups.

M is preferably 2H, 2Li, 2Na, 2K, Mg, Ca, Ba, Al, Si, Sn, Pb, Rh, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, AIX, GaX, InX or SiX₂, where in X is OH or Cl, more preferably 2H, Sc, Ti, Va, Cr, Mn, Fe, Co, Zn, Ni and Cu, especially Cu or Ni and more especially Cu.

Preferably R¹ and R² independently are H, methyl, ethyl, hydroxyethyl or ethyl sulfonic acid.

Preferably R¹ and R² are independently methyl or H.

More preferably R¹ and R² are both H.

L is preferably -alkylene-, optionally substituted or optionally interrupted by a hetero atom or a double or triple carbon to carbon bond; optionally substituted -arylene-; or optionally substituted -heterocycylene-.

More preferably L is optionally substituted C₁₋₄ alkylene, especially unsubstituted C₁₋₄ alkylene. It is particularly preferred that L is —C₂H₄—.

Optional substituents for R¹, R² and L, when it comprises optionally substituted -alkylene-, are preferably, independently, optionally substituted alkoxy (preferably C₁₋₄-alkoxy), optionally substituted aryl (preferably phenyl), optionally substituted aryloxy (preferably phenoxy), optionally substituted heterocyclyl (preferably triazinyl), polyalkylene oxide (preferably polyethylene oxide or polypropylene oxide), CO₂H, SO₃H, PO₃H₂, nitro, cyano, halo (preferably Cl and Br), ureido, —SO₂F, hydroxy, ester, —NR^(a)R^(b), COR^(a), —CONR^(a)R^(b), —NHCOR^(a), carboxyester, sulfone, and —SO₂NR^(a)R^(b) wherein R^(a) and R^(b) are each independently H or optionally substituted alkyl (especially C₁₋₄-alkyl). Optional substituents for any of the above substituents may be selected from the same list of substituents.

The optional substituents present on B or L when it is optionally substituted -arylene- or optionally substituted -heterocycylene- are independently selected from optionally substituted alkyl (preferably C₁₋₄-alkyl), optionally substituted alkoxy (preferably C₁₋₄-alkoxy), optionally substituted aryl (preferably phenyl), optionally substituted aryloxy (preferably phenoxy), optionally substituted heterocyclic, polyalkylene oxide (preferably polyethylene oxide or polypropylene oxide), carboxy, phosphato, sulfo, nitro, cyano, halo, ureido, —SO₂F, hydroxy, ester, —NR^(a)R^(b), —COR^(a), —CONR^(a)R^(b), —NHCOR^(a), carboxyester, sulfone, and —SO₂NR^(a)R^(b), wherein R^(a) and R^(b) are each independently H or optionally substituted alkyl (especially C₁₋₄-alkyl). Optional substituents for any of the substituents described above may be selected from the same list of substituents.

Preferably B is H, —OH, —NH₂, or substituted —O, —S or —N.

In one embodiment B comprises at least one anionic group especially carboxy and/or sulfo.

It is especially preferred that when B is other than H then it is selected from the group consisting of —OH, —NHCH₃, —N(CH₃)₂, —NHC₂H₄SO₃H, —N(CH₃)C₂H₄SO₃H, —NC₃H₆SO₃H, —NHdisulfophenyl, —NHsulfophenyl, —NHcarboxyphenyl or —NHdicarboxyphenyl, —NHsulfonaphthyl, —NHdisulfonaphthyl, —NHtrisulfonaphthyl, —NHcarboxyonaphthyl, —NHdicarboxyonaphthyl, NHtricarboxyonaphthyl, —NHsulfohetercyclyl, —NHdisulfohetercyclyl or —NHtrisulfohetercyclyl.

Preferably x is 0.1 to 2, more preferably 0.2 to 1.5, especially 0.3 to 1.0 and more especially 0.3 to 0.8.

Preferably y is 0.1 to 0.9, more preferably 0.2 to 0.8, especially 0.2 to 0.7 and more especially 0.3 to 0.7.

Preferably x is 0.1 to 3.5, more preferably 0.5 to 3, especially 0.8 to 3.0 and more especially 1.0 to 3.

The sum of (x+y+z) is preferably 3 to 4, more preferably the sum of (x+y+z) is 4.

The dyes of Formula (1) are free from fibre reactive groups. The term fibre reactive group is well known in the art and is described for example in EP 0356014 A1. Fibre reactive groups are capable, under suitable conditions, of reacting with the hydroxyl groups present in cellulosic fibres or with the amino groups present in natural fibres to form a covalent linkage between the fibre and the dye. As examples of fibre reactive groups excluded from the dyes of Formula (1) there may be mentioned aliphatic sulfonyl groups which contain a sulfate ester group in beta-position to the sulfur atom, e.g. beta-sulfato-ethylsulfonyl groups, alpha, beta-unsaturated acyl radicals of aliphatic carboxylic acids, for example acrylic acid, alpha-chloro-acrylic acid, alpha-bromoacrylic acid, propiolic acid, maleic acid and mono- and dichloro maleic; also the acyl radicals of acids which contain a substituent which reacts with cellulose in the presence of an alkali, e.g. the radical of a halogenated aliphatic acid such as chloroacetic acid, beta-chloro and beta-bromopropionic acids and alpha, beta-dichloro- and dibromopropionic acids or radicals of vinylsulfonyl- or beta-chloroethylsulfonyl- or beta-sulfatoethyl-sulfonyl-endo-methylene cyclohexane carboxylic acids. Other examples of cellulose reactive groups are tetrafluorocyclobutyl carbonyl, trifluoro-cyclobutenyl carbonyl, tetrafluorocyclobutylethenyl carbonyl, trifluoro-cyclobutenylethenyl carbonyl; activated halogenated 1,3-dicyanobenzene radicals; and heterocyclic radicals which contain 1, 2 or 3 nitrogen atoms in the heterocyclic ring and at least one cellulose reactive substituent on a carbon atom of the ring, for example a triazinyl halide.

The mixture of dyes of Formula (1) are preferably prepared by a process comprising cyclisation of a β-substituted phthalic acid or analogue thereof. Preferred β-substituted phthalic acid analogues include phthalonitrile, iminoisoindoline, phthalic anhydride, phthalimide and phthalamide or mixtures thereof.

The cyclisation reaction may be carried out in the presence of a suitable source of ammonia (if required), and (if required) a suitable metal salt, for example CuCl₂, and a base such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) followed by, if required, further synthetic steps, for example, chlorination and then amination/amidation.

The total amount of x+y+z may be controlled by varying the degree and ratio of substituted phthalic acid or analogue thereof to unsubstituted phthalic acid or analogue thereof. Thus, when mono-substituted phthalic acid or analogue thereof is used in the cyclisation reaction then x+y+z is 4.

In a preferred synthetic preparation of phthalocyanine dyes of Formula (1) the phthalocyanine ring is prepared by the cyclisation of 4-sulfophthalic acid, preferably to phthalocyanine β-tetrasulfonic acid.

When a phthalocyanine β-sulfonic acid is an intermediate in a route to dyes of Formula (1) it may be chlorinated by reacting with any suitable chlorinating agent.

Chlorination is preferably carried out by treating the phthalocyanine β-sulfonic acid with chlorosulfonic acid preferably in the presence of an acid halide such as thionyl chloride, sulfuryl chloride, phosphorous pentachloride, phosphorous oxychloride or phosphorous trichloride.

The —SO₂Cl substituent, so formed, on the phthalocyanine ring is then further reacted with ammonia and (either sequentially or at the same time) a compound of formula:

or with ammonia and (either sequentially or at the same time) a compound of formula HR¹N-L-NR²H, the product of which can then be reacted with cyanuric chloride and then with dimethylamine and B (or an activated precursor) either singly or at the same time.

A skilled person will appreciate that the product of these reactions will be a disperse mixture and so the values of x, y and z will represent an average of the groups present in the mixture.

This reaction yields a mixture of phthalocyanine dyes of Formula (1).

The dyes of Formula (1) are preferably free from substituents, other than H, in the α-position of the phthalocyanine ring.

The mixture of dyes of Formula (1) have attractive, strong cyan shades and are valuable colorants for use in the preparation of ink-jet printing inks. They benefit from a good balance of solubility, storage stability and fastness to water and light.

Acid or basic groups on the dyes of Formula (1), particularly acid groups, are preferably in the form of a salt. Thus, the Formulae shown herein include the dyes in salt form.

Preferred salts are alkali metal salts, especially lithium, sodium and potassium, ammonium and substituted ammonium salts (including quaternary amines such as ((CH₃)₄N⁺) and mixtures thereof. Especially preferred are salts with sodium, lithium, ammonia and volatile amines, more especially sodium salts. Dyes of Formula (1) may be converted into a salt using known techniques.

The dyes of Formula (1) may exist in tautomeric forms other than those shown in this specification. These tautomers are included within the scope of the present invention.

According to a second aspect of the present invention there is provided a composition comprising a mixture of dyes of Formula (1) as described in the first aspect of the invention and a liquid medium.

Preferred compositions according to the second aspect of the invention comprise:

-   -   (a) from 0.01 to 30 parts of a mixture of dyes of Formula (1) as         described in the first aspect of the invention; and     -   (b) from 70 to 99.99 parts of a liquid medium;         wherein all parts are by weight.

Preferably the number of parts of (a)+(b)=100.

The number of parts of component (a) is preferably from 0.1 to 20, more preferably from 0.5 to 15, and especially from 1 to 5 parts by weight. The number of parts of component (b) is preferably from 80 to 99.9, more preferably from 85 to 99.5 and especially from 95 to 99 parts by weight.

Preferably component (a) is completely dissolved in component (b). Preferably component (a) has a solubility in component (b) at 20° C. of at least 10%. This allows the preparation of liquid dye concentrates that may be used to prepare more dilute inks and reduces the chance of the dye precipitating if evaporation of the liquid medium occurs during storage.

The inks may be incorporated in an ink-jet printer as a high concentration cyan ink, a low concentration cyan ink or both a high concentration and a low concentration ink. In the latter case this can lead to improvements in the resolution and quality of printed images. Thus the present invention also provides a composition (preferably an ink) where component (a) is present in an amount of 2.5 to 7 parts, more preferably 2.5 to 5 parts (a high concentration ink) or component (a) is present in an amount of 0.5 to 2.4 parts, more preferably 0.5 to 1.5 parts (a low concentration ink).

Preferred liquid media include water, a mixture of water and organic solvent and organic solvent free from water. Preferably the liquid medium comprises a mixture of water and organic solvent or organic solvent free from water.

When the liquid medium (b) comprises a mixture of water and organic solvent, the weight ratio of water to organic solvent is preferably from 99:1 to 1:99, more preferably from 99:1 to 50:50 and especially from 95:5 to 80:20.

It is preferred that the organic solvent present in the mixture of water and organic solvent is a water-miscible organic solvent or a mixture of such solvents. Preferred water-miscible organic solvents include C₁₋₆-alkanols, preferably methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol and cyclohexanol; linear amides, preferably dimethylformamide or dimethylacetamide; ketones and ketone-alcohols, preferably acetone, methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscible ethers, preferably tetrahydrofuran and dioxane; diols, preferably diols having from 2 to 12 carbon atoms, for example pentane-1,5-diol, ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol and thiodiglycol and oligo- and poly-alkyleneglycols, preferably diethylene glycol, triethylene glycol, polyethylene glycol and polypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol; mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers of diols having 2 to 12 carbon atoms, especially 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol, 2-[2-(2-methoxyethoxy)ethoxy]ethanol, 2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol and ethyleneglycol monoallylether; cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclic esters, preferably caprolactone; sulfoxides, preferably dimethyl sulfoxide and sulfolane. Preferably the liquid medium comprises water and 2 or more, especially from 2 to 8, water-miscible organic solvents.

Especially preferred water-miscible organic solvents are cyclic amides, especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone; diols, especially 1,5-pentane diol, ethyleneglycol, thiodiglycol, diethyleneglycol and triethyleneglycol; and mono-C₁₋₄-alkyl and C₁₋₄-alkyl ethers of diols, more preferably mono-C₁₋₄-alkyl ethers of diols having 2 to 12 carbon atoms, especially 2-methoxy-2-ethoxy-2-ethoxyethanol.

Examples of further suitable liquid media comprising a mixture of water and one or more organic solvents are described in U.S. Pat. No. 4,963,189, U.S. Pat. No. 4,703,113, U.S. Pat. No. 4,626,284 and EP425,150A.

When the liquid medium comprises organic solvent free from water, (i.e. less than 1% water by weight) the solvent preferably has a boiling point of from 30° to 200° C., more preferably of from 40° to 150° C., especially from 50 to 125° C. The organic solvent may be water-immiscible, water-miscible or a mixture of such solvents. Preferred water-miscible organic solvents are any of the hereinbefore-described water-miscible organic solvents and mixtures thereof. Preferred water-immiscible solvents include, for example, aliphatic hydrocarbons; esters, preferably ethyl acetate; chlorinated hydrocarbons, preferably CH₂Cl₂; and ethers, preferably diethyl ether; and mixtures thereof.

When the liquid medium comprises a water-immiscible organic solvent, preferably a polar solvent is included because this enhances solubility of the mixture of phthalocyanine dyes in the liquid medium. Examples of polar solvents include C₁₋₄-alcohols.

In view of the foregoing preferences it is especially preferred that where the liquid medium is organic solvent free from water it comprises a ketone (especially methyl ethyl ketone) and/or an alcohol (especially a C₁₋₄-alkanol, more especially ethanol or propanol).

The organic solvent free from water may be a single organic solvent or a mixture of two or more organic solvents. It is preferred that when the liquid medium is organic solvent free from water it is a mixture of 2 to 5 different organic solvents. This allows a liquid medium to be selected that gives good control over the drying characteristics and storage stability of the ink.

Liquid media comprising organic solvent free from water are particularly useful where fast drying times are required and particularly when printing onto hydrophobic and non-absorbent substrates, for example plastics, metal and glass.

The liquid media may of course contain additional components conventionally used in ink-jet printing inks, for example viscosity and surface tension modifiers, corrosion inhibitors, biocides, kogation reducing additives and surfactants which may be ionic or non-ionic.

Although not usually necessary, further colorants may be added to the ink to modify the shade and performance properties. Examples of such colorants include C.I. Direct Yellow 86, 132, 142 and 173; C.I. Direct Blue 307; C.I. Food Black 2; C.I. Direct Black 168 and 195; and C.I. Acid Yellow 23.

It is preferred that the composition according to the invention is ink suitable for use in an ink-jet printer. Ink suitable for use in an ink-jet printer is ink which is able to repeatedly fire through an ink-jet printing head without causing blockage of the fine nozzles.

Ink suitable for use in an ink-jet printer preferably has a viscosity of less than 20 cP, more preferably less than 10 cP, especially less than 5 cP, at 25° C.

Ink suitable for use in an ink-jet printer preferably contains less than 500 ppm, more preferably less than 250 ppm, especially less than 100 ppm, more especially less than 10 ppm in total of divalent and trivalent metal ions (other than any divalent and trivalent metal ions bound to a dye of Formula (1) or any other colourant or additive incorporated in the ink).

Preferably ink suitable for use in an ink-jet printer has been filtered through a filter having a mean pore size below 10 μm, more preferably below 3 μm, especially below 2 μm, more especially below 1 μm. This filtration removes particulate matter that could otherwise block the fine nozzles found in many ink-jet printers.

Preferably ink suitable for use in an ink-jet printer contains less than 500 ppm, more preferably less than 250 ppm, especially less than 100 ppm, more especially less than 10 ppm in total of halide ions.

A third aspect of the invention provides a process for forming an image on a substrate comprising applying ink suitable for use in an ink-jet printer, according to the second aspect of the invention, thereto by means of an ink-jet printer.

The ink-jet printer preferably applies the ink to the substrate in the form of droplets that are ejected through a small orifice onto the substrate. Preferred ink-jet printers are piezoelectric ink-jet printers and thermal ink-jet printers. In thermal ink-jet printers, programmed pulses of heat are applied to the ink in a reservoir by means of a resistor adjacent to the orifice, thereby causing the ink to be ejected from the orifice in the form of small droplets directed towards the substrate during relative movement between the substrate and the orifice. In piezoelectric ink-jet printers the oscillation of a small crystal causes ejection of the ink from the orifice. Alternately the ink can be ejected by an electromechanical actuator connected to a moveable paddle or plunger, for example as described in International Patent Application WO00/48938 and International Patent Application WO00/55089.

The substrate is preferably paper, plastic, a textile, metal or glass, more preferably paper, an overhead projector slide or a textile material, especially paper.

Preferred papers are plain or treated papers which may have an acid, alkaline or neutral character. Glossy papers are especially preferred.

A fourth aspect of the present invention provides a material preferably paper, plastic, a textile, metal or glass, more preferably paper, an overhead projector slide or a textile material, especially paper more especially plain, coated or treated papers printed with a mixture of dyes as described in the first aspect of the invention, a composition according to the second aspect of the invention or by means of a process according to the third aspect of the invention.

It is especially preferred that the printed material of the fourth aspect of the invention is a photograph printed using a process according to the third aspect of the invention.

A fifth aspect of the present invention provides an ink-jet printer cartridge comprising a chamber and an ink suitable for use in an ink-jet printer wherein the ink is in the chamber and the ink is as defined in the second aspect of the present invention. The cartridge may contain a high concentration ink and a low concentration ink, as described in the second aspect of the invention, in different chambers.

The invention is further illustrated by the following Examples in which all parts and percentages are by weight unless otherwise stated.

EXAMPLE 1 Analysis of Dyes of Formula (1)

Confirmation of the structure of dyes of Formula (1) is by mass spectrometry. Elemental analysis is used to determine the ratios of x, y and z. Thus, in the dyes of the examples below mass spectrometry has shown that in all cases x+y+z is 4. When the sum of x plus y and z, as determined by elemental analysis is not exactly 4 this is thought to be due to the presence of impurities. The presence of these impurities and their effect on the estimated values of x, y and z would be well known to a person skilled in the art who would appreciate that the value of x plus y plus z should not exceed 4 and who would treat the experimentally determined values of x, y and z as indicative of the ratios of the groups. Preparation of a Mixture of Dyes of Formula:

The expected values of x, y and z in the compound of Example 1 are based on the molar equivalents of ammonia and triazinyl amine used in Stage 4 below

Stage 1—Preparation of β-Substituted Copper Phthalocyanine Tetra Sulfonic Acid

Potassium 4-sulfophthalic acid (56.8 g), urea (120 g), CuCl₂ (6.9 g), ammonium molybdate (1.2 g) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (7.5 g) were mixed in a reaction vessel. The mixture was then warmed in stages (130° C./30 minutes, 150° C./30 minutes,180° C./30 minutes, 220° C.) over 2 hours and the melt which formed was stirred at 220° C. for a further 2 hours. The solid that formed was extracted 4 times with hot water (4×200 ml) and the extract was filtered to remove insoluble material. The resultant filtrate was stirred at between 60° C.-70° C. and then sufficient NaCl was added to give a 7% salt solution. Stirring was continued and the solid that precipitated was filtered, washed with a 10% salt solution (200 ml) and pulled dry by vacuum. The resultant damp solid (77.6 g) was slurried in acetone, filtered and dried first at room temperature and then at 50° C.

Stage 2

Preparation of β-Substituted Copper Phthalocyanine Sulfonyl Chloride:

Phosphorous oxychloride (8.48 g) was added to chlorosulfonic acid (86 g) at 28° C. The product of stage 1 (16 g) was then added to this mixture over 10-15 minutes while keeping temperature below 60° C. This reaction mixture was warmed to 140° C. and kept at this temperature, with stirring for 6.5 hours. At the end of this time the reaction mixture was cooled and stirred at room temperature overnight. The next day the reaction-melt was added to a mixture of water/ice (100 g/150 g), while keeping the temperature below 0° C., using external cooling and the further addition of ice as necessary. The resultant suspension was filtered and washed with an acidified ice cold water (100 ml) to give the product (50.9 g) as a damp paste.

Stage 3

Preparation of the Triazinyl Amine

2,5-Disulfoaniline (13.8 g) was dissolved in water with sodium hydroxide solution at pH7 and added dropwise to a slurry of cyanuric chloride (9.28 g) in water (200 ml) and calsolene oil (few drops) at pH 5 to 6 and 5° C. The pH of the reaction was maintained by the addition of dilute sodium hydroxide. After 2 hours the pH was raised to 7 and the reaction was left at 25° C. for 0.5 hours and then filtered. Dimethylamine (40% strength) (6.3 ml) was added to the filtrate, the pH was raised to pH 8.5 to 9 and the reaction was help at 25° C. for 2 hours. The reaction was then stirred for 1 hour at 60° C. and then for 1 hour 80° C. maintaining the pH at pH 9-10. The reaction was allowed to cool to room temperature overnight. The next day ethylene diamine (33 ml) was added and the reaction was heated at 80° C. for 2 hours. The resultant product was isolated by concentrating the reaction mixture to low volume(200 ml), adding salt(20 g) and lowering the pH to 1 with concentrated hydrochloric acid. The precipitated solid was filtered and washed with 20% sodium chloride solution(50 ml). The precipitate was stirred in a mixture of methanol(170 ml) and water(9 ml) at room temperature and then at 60° C. for 1 hour, allowed to cool and filtered, washed with methanol(25 ml) and dried to give the required product as a white solid (18.5 g).

Stage 4

Preparation of the Title Dye

The phthalocyanine sulfonyl chloride from stage 2 (24.45 g) in ice/water(150 ml) was added to a stirred mixture of the triazinyl amine from stage 3 (9.5 g) in ice cold water (50 ml) at 0-5° C. and 0.88 ammonia (0.062 g). The pH was raised to 9.5 via the addition of dilute sodium hydroxide, stirred at 0 to 5° C. for 1 hour, at 60° for 1 hour and then at 80° C. and pH 9.5-10 for 1 hour. Sodium chloride (to 20%) was added and pH was lowered to 1 with concentrated hydrochloric acid. The resultant precipitate was then collected by filtration, washed with a 20% sodium chloride solution (50 ml), dialysed to low conductivity and then dried. Micro analysis of the product revealed x=0.2, y=2.2 and z=1.5.

EXAMPLES 2 TO 4

Examples 2 to 4 were prepared as described in Example 1 except that in Stage 4, ammonium chloride was used in place of ammonia and the ratio of the substituents represented by x, y and z was varied by varying the ratio of ammonium chloride and triazinyl amine used. The values of x, y and z were determined by elemental microanalysis. Source and amount of Equivalents of Example Ammonia Triazine value for x value for y value for z 2 0.5 equivalents 3 equivalents Unable to Unable to Unable to of ammonium of triazinyl calculate calculate calculate chloride amine 3 2.0 equivalents 1 equivalent of Unable to Unable to Unable to of ammonium triazinyl amine calculate calculate calculate chloride 4 1.0 equivalent 2 equivalents 1.4 1   1.4 of ammonium of triazinyl chloride amine 5 1.0 equivalent 3 equivalents 1.3 0.5 1.9 of ammonium of triazinyl chloride amine 6 2.0 equivalent 2 equivalents 2.0 0.1 1.5 of ammonium of triazinyl chloride amine

EXAMPLE 7

Phthalocyanine sulfonyl chloride (31.75 g) (prepared as in Stage 1 and Stage 2 of Example 1) in ice/water(130 ml) was added to a stirred mixture of the triazinyl amine from Example 1, Stage 3 (3.16 g) in water (50 ml) at 0-5° C. The pH was raised to 9 via the addition of 28% ammonia. The reaction mixture was stirred at 0 to 5° C. for 1 hour, at 60°, pH9-9.5 for 1 hour and then at 80° C. and pH 9-10.5 for 1 hour. The pH was maintained by the addition of ammonia. Sodium chloride (to 20%) was added and the pH was lowered to 1 with concentrated hydrochloric acid. The precipitate which formed was collected by filtration, washed with 20% solution of sodium chloride (50 ml), dialysed to low conductivity and dried to give 7 g of product.

EXAMPLES 8 to 9

Examples 8 to 9 were prepared as described in Example 7. The ratio of the substituents represented by x, y and z was varied by varying the amount of triazinyl amine used. The values of x, y and z were determined by elemental microanalysis. Equivalents Example of Triazine value for x value for y value for z 8 2 equivalents 1.9 1.2 0.9 of triazinyl amine 9 3 equivalent 1.4 1.6 1.0 of triazinyl amine Ink and Ink-Jet Printing

Ink may be prepared from the dyes of Examples 1 to 9 by dissolving 3 g of the dye in 97 ml of a liquid medium consisting of 5 parts 2-pyrrolidone; 5 parts thiodiethylene glycol; 1 part Surfynol™ 465 and 89 parts water and adjusting the pH to between pH 8 to 9 with sodium hydroxide. Surfynol™ 465 is a surfactant from Air Products.

Ink-Jet Printing

Ink, prepared as described above, may be filtered through a 0.45 micron nylon filter and then incorporated into an empty print cartridge using a syringe.

The ink can then be ink-jet printed onto either plain paper or specialist media.

Print Evaluation

Prints, formed by ink-jet printing, may be tested for ozone fastness by exposure to 1 ppm ozone at 40° C., 50% relative humidity, for 24 hrs in a Hampden 903 Ozone cabinet. Fastness of the printed ink to ozone can be judged by the difference in the optical density before and after exposure to ozone.

Light-fastness of the printed image may be assessed by fading the printed image in an Atlas Ci5000 Weatherometer for 100 hours and then measuring the change in the optical density.

Optical density measurements can be performed using a Gretag spectrolino spectrophotometer set to the following parameters: Measuring Geometry 45°/0° Spectral Range 380-730 nm Spectral Interval 10 nm Illuminant D65 Observer 2° (CIE 1931) Density Ansi A External Filler None

Light and Ozone fastness should be assessed by the percentage change in the optical density of the print, where a lower figure indicates higher fastness, and the degree of fade. The degree of fade can be expressed as ΔE and a lower figure indicates higher light fastness. ΔE is defined as the overall change in the CIE colour co-ordinates L, a, b of the print and is expressed by the equation ΔE=(ΔL²+Δa²+Δb²)0.5.

Further Inks

The inks described in Tables A and B may be prepared wherein the Dye described in the first column is the Dye made in the above Example of the same number. Numbers quoted in the second column onwards refer to the number of parts of the relevant ingredient and all parts are by weight. The inks may be applied to paper by thermal or piezo ink-jet printing.

The following abbreviations are used in Tables A and B:

PG=propylene glycol

DEG=diethylene glycol

NMP=N-methyl pyrrolidone

DMK=dimethylketone

IPA=isopropanol

MEOH=methanol

2P=2-pyrrolidone

MIBK=methylisobutyl ketone

P12=propane-1,2-diol

BDL=butane-2,3-diol

CET=cetyl ammonium bromide

PHO=Na₂HPO₄ and

TBT=tertiary butanol

TDG=thiodiglycol TABLE A Dye Dye Na Example Content Water PG DEG NMP DMK NaOH Stearate IPA MEOH 2P MIBK 1 2.0 80 5 6 4 5 2 3.0 90 5 5 0.2 1 10.0 85 3 3 3 5 1 2 2.1 91 8 1 1 3.1 86 5 0.2 4 5 2 1.1 81 9 0.5 0.5 9 1 2.5 60 4 15 3 3 6 10 5 4 2 5 65 20 10 1 2.4 75 5 4 5 6 5 2 4.1 80 3 5 2 10 0.3 1 3.2 65 5 4 6 5 4 6 5 1 5.1 96 4 1 10.8 90 5 5 1 10.0 80 2 6 2 5 1 4 1 1.8 80 5 15 1 2.6 84 11 5 1 3.3 80 2 10 2 6 1 12.0 90 7 0.3 3 1 5.4 69 2 20 2 1 3 3 1 6.0 91 4 5

TABLE B Dye Dye Example Content Water PG DEG NMP CET TBT TDG BDL PHO 2P PI2 1 3.0 80 15 0.2 5 2 9.0 90 5 1.2 5 1 1.5 85 5 5 0.15 5.0 0.2 2 2.5 90 6 4 0.12 1 3.1 82 4 8 0.3 6 2 0.9 85 10 5 0.2 1 8.0 90 5 5 0.3 2 4.0 70 10 4 1 4 11 1 2.2 75 4 10 3 2 6 1 10.0 91 6 3 1 9.0 76 9 7 3.0 0.95 5 1 5.0 78 5 11 6 1 5.4 86 7 7 1 2.1 70 5 5 5 0.1 0.2 0.1 5 0.1 5 1 2.0 90 10 1 2 88 10 1 5 78 5 12 5 1 8 70 2 8 15 5 1 10 80 8 12 1 10 80 10 

1. A mixture of dyes of Formula (1) and salts thereof:

wherein: M is 2H, Si, a metal, an oxymetal group, a hydroxymetal group or a halometal group; Pc represents a phthalocyanine nucleus of formula

R¹ and R² independently are H or optionally substituted C₁₋₄alkyl; L is a divalent linking group; B is a substituent. x is 0.1 to 3.8; y is 0.1 to 3.8; z is 0.1 to 3.8; the sum of (x+y+z) is 2 to 4;and the substituents, represented by x, y and z, are only attached to a β position on the phthalocyanine ring and the dyes are free from fibre reactive groups.
 2. A mixture of dyes according to claim 1 wherein y is 0.1 to 0.9.
 3. A mixture of dyes according to either claim 1 or claim 2 wherein M is Cu.
 4. A mixture of dyes according to claim 1 or claim 2 wherein R¹ and R² are independently methyl or H.
 5. A mixture of dyes according to claim 1 or claim 2 wherein R¹ and R² are both H.
 6. A mixture of dyes according to claim 1 or claim 2 wherein L is optionally substituted C₁₋₄ alkylene.
 7. A mixture of dyes according to claim 1 or claim 2 wherein B is H, —OH, —SH, —NH₂, or substituted —O, —S or —N.
 8. A mixture of dyes according to claim 1 or claim 2 wherein B is selected from the group consisting of —OH, —NHCH₃, —N(CH₃)₂, —NHC₂H₄SO₃H, —N(CH₃)C₂H₄SO₃H, —NC₃H₆SO₃H, —NHdisulfophenyl, —NHsulfophenyl, —NHcarboxyphenyl or—NHdicarboxyphenyl, —NHsulfonaphthyl, —NHdisulfonaphthyl, —NHtrisulfonaphthyl, —NHcarboxyonaphthyl, NHdicarboxyonaphthyl, NHtricarboxyonaphthyl, —NHsulfohetercyclyl, —NHdisulfohetercyclyl, or —NHtrisulfohetercyclyl.
 9. A mixture of dyes according to claim 1 or claim 2 wherein the sum of (x+y+z) is
 4. 10. A mixture of dyes according to claim 1 or claim 2 prepared by a process comprising cyclisation of a β-substituted phthalic acid or analogue thereof.
 11. A mixture of dyes according to claim 1 or claim 2 free from substituents, other than H, in the α-position of the phthalocyanine ring.
 12. A composition comprising a mixture of dyes of Formula (1) as described in claim 1 and a liquid medium.
 13. A composition according to claim 12 which comprises: (a) from 0.01 to 30 parts of a mixture of dyes of Formula (1) as described in any one of claims 1 to 12; and (b) from 70 to 99.99 parts of a liquid medium; wherein all parts are by weight.
 14. A composition according to either claim 12 or claim 13 which is ink suitable for use in an ink-jet printer.
 15. A process for forming an image on a substrate comprising applying ink according to claim 14 thereto by means of an ink-jet printer.
 16. A material printed by means of a process according to claim
 15. 17. A material according to claim 16 which is a photograph.
 18. An ink-jet printer cartridge comprising a chamber and an ink according to claim 14 wherein the ink is in the chamber. 